Climate Science Glossary

Term Lookup

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Term:

Settings

Beginner Intermediate Advanced No DefinitionsDefinition Life:

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

What were climate scientists predicting in the 1970s?

What the science says...

Climate Myth...

Ice age predicted in the 70s"[M]any publications now claiming the world is on the brink of a global warming disaster said the same about an impending ice age – just 30 years ago. Several major ones, including The New York Times, Time magazine and Newsweek, have reported on three or even four different climate shifts since 1895." (Fire and Ice)

In the thirty years leading up to the 1970s, available temperature recordings suggested that there was a cooling trend. As a result some scientists suggested that the current inter-glacial period could rapidly draw to a close, which might result in the Earth plunging into a new ice age over the next few centuries. This idea could have been reinforced by the knowledge that the smog that climatologists call ‘aerosols’ – emitted by human activities into the atmosphere – also caused cooling. In fact, as temperature recording has improved in coverage, it’s become apparent that the cooling trend was most pronounced in northern land areas and that global temperature trends were in fact relatively steady during the period prior to 1970.

At the same time as some scientists were suggesting we might be facing another ice age, a greater number published contradicting studies. Their papers showed that the growing amount of greenhouse gasses that humans were putting into the atmosphere would cause much greater warming – warming that would exert a much greater influence on global temperature than any possible natural or human-caused cooling effects.

By 1980 the predictions about ice ages had ceased, due to the overwhelming evidence contained in an increasing number of reports that warned of global warming. Unfortunately, the small number of predictions of an ice age appeared to be much more interesting than those of global warming, so it was those sensational 'Ice Age' stories in the press that so many people tend to remember.

Check out this New York Times article from 1956 that discusses a forecasted increase in global temperatures as emissions from burning fossil fuels increase atmospheric CO2. Thanks to George Morrison for the heads up.

The 1979 report from the National Academy of Sciences, "Carbon Dioxide and Climate: A Scientific Assessment" finds "when it is assumed that the CO2 content of the atmosphere is doubled and statistical thermal equilibrium is achieved, the more realistic of the modeling efforts predict a global surface warming of between 2°C and 3.5°C, with greater increases at high latitudes."

Further viewing

"In the 70s, They said there'd be an Ice Age" from Climate Denial Crock of the Week.

Comments

But the idea that we will go into another glaciation is far sounder science than is this new and basically baseless stuff. We always have in the past. This planet is currently hard-wired with a one way catastrophic cooling bias.

The case that we will have another glaciation is basically cut and dried. We have the capacity to cool the earth. We have no such capacity to warm the earth. In order to avoid another glaciation we ought to be looking at ways to hose down volcanic aerosols or something.

Certainly we need to build up our nuclear energy production capacity. And our hydrocarbons as well.

The claim by Peterson that there were only 7 papers in the 1970s predicting cooling is just ridiculous. Anyone can check this with a quick look at Google scholar. Here are two examples they have missed, but there are many more.

Return of the ice age and drought in peninsular Florida?
Joseph M. Moran, Geology 3 (12): 695-696 (1975)
Convection in the Antarctic Ice Sheet Leading to a Surge of the Ice Sheet and Possibly to a New Ice Age
T. Hughes, Science Vol. 170. no. 3958, pp. 630 - 633 (1970)

What is strange is why people attempt to re-write recent history in this way, when their claims can so easily be disproven.
Where did all the stories in the papers, TV and magazines come from? Were they all just fabricated? No of course not, they came from scientists who made suggestions (like the above 'possibly to a new ice age') which were then hyped and exaggerated by the media. Much the same thing is happening now with the global warming scare.

Um, for one thing Moran was writing about _Florida_ cooling, not _global_ cooling. I guess you'll need to relax your search criterion for "global cooling" a whole lot to prove that scientists did predict cooling...

"they came from scientists who made suggestions (like the above 'possibly to a new ice age') which were then hyped and exaggerated by the media. Much the same thing is happening now with the global warming scare."

Yeah, "much of the same thing" in the sense that the "media" is artificially inflating the voice of the global warming "skeptics".

frankbi
Read the media articles, they are almost always alarmist. Those that have comment sections often disappear after someone disproves the article. I have seen this on CBS, ABC and LiveScience quite a few times.
Then there is the BBC.

PaulM,
You bemoan people attempting to [quote]‘re-write recent history’. However, reporting the facts does not amount to ‘rewriting history’!
The people actually responsible for the rewriting of history are not AGW fanatics, but people politically or ideologically aligned to industry and typically funded directly or indirectly by the fossil fuel funded denial industry. Peterson et al. 2008 have merely attempted to establish the facts and set the record straight.

The fact that you may have identified two additional relevant papers and claimed there are ‘many more’, which may or may not support your pet theory, does not invalidate their research. It seems probable that any additional papers fitting the various search criteria will be distributed in much the same way as the papers already listed, unless there is a very good reason why they should not be included.

Quietman
You are repeating the deceitful alarmist allegations made repeatedly by skeptics

From Scientists add to heat over global warming by S. Fred Singer
Washington Times, May 5, 1998
“But this exaggerated concern about global warming contrasts sharply with an earlier NAS/NRC report, "Understanding Climate Change: A Program for Action." There, in 1975, the NAS "experts" exhibited the same hysterical fears—-this time, however, asserting a "finite possibility that a serious worldwide cooling could befall the Earth within the next 100 years."

The 1975 NAS panel claimed to have good reason for their fears: Global temperatures had been in steady decline since the 1940s. They considered the preceding period of warming, between 1860 and 1940, as "unusual," following as it did the "Little Ice Age," which had lasted from 1430 to 1850.”

http://www.sepp.org/key%20issues/glwarm/sciaddheat.html

You will note that the terms ‘exaggerated’, ‘hysterical fears’ and ‘fears’ are used. There are a number of other changes too that render the use of quotes highly questionable.

1975 US National Academy of Sciences/National Research Council Report
UNDERSTANDING CLIMATE CHANGE: A program for action

Strangely,

From the foreword (by V E Suomi, Chair of the US Committee for GARP):

"..,we do not have a good quantitative understanding of our climate machine and what determines its course. Without the fundamental understanding, it does not seem possible to predict climate..,".

From the introduction
"Climatic change has been a subject of intellectual interest for many years. However, there are now more compelling reasons for its study: the growing awareness that our economic and social stability is profoundly influenced by climate and that man's activities themselves may be capable of influencing the climate in possibly undesirable ways. The climates of the earth have always been changing, and they will doubtless continue to do so in the future. How large these future changes will be, and where and how rapidly they will occur, we do not know".

Not much evidence of hysteria! It would seem that the allegations of exaggeration and hysteria were complete fabrications introduced by Singer. The measured and cautious language of the National Academy of Sciences has been entirely born out.

Re: "You are repeating the deceitful alarmist allegations made repeatedly by skeptics"
No, I am not repeating anything. My statement is purely from personal experience. I tried again this morining, after reading your reply, to go back and see if some of the alarmist articles were still there. Most were gone. I checked back through January - gone. What few skeptical articles I had read are still there. I may be ignorant about many subjects but I am not stupid. Those articles were intentionally pulled when proven incorrect. Here are the few that have not been deleted:

My point being that healthy skepticism leads to better understanding of the big picture.

Response: I'll leave this comment up as there are few links there I wasn't previously aware of. But from now on, I'm taking a zero tolerance policy on comments that post a bunch of links not related to the topic. I know its a bit more work but please post any links on the relevant page.

Sorry John
I was replying to ScaredAmoeba "You are repeating the deceitful alarmist allegations made repeatedly by skeptics" Attempting to show that not all skeptical arguments are denials or harmful. If you prefer to delete it thats OK by me, it's your blog.

Response: Nah, I'll leave it up. One of my pet peeves when having online discussion about global warming is when someone just posts a whole bunch of diverse links to a wide range of topics - it essentially shuts down the discussion because it's not practical to post a reply addressing each link. More constructive debate keeps to the topic at hand. I don't think you were necessarily trying to do this but for future reference, those links would be more effective posted on the appropriate page. Plus from my point of view as webmaster, I like the comments section to be relevant and useful to readers.

The side argument over deceit aside, I would like to point out that the scientist who started the cooling fright in the 70s actually has not changed his position.
Reading his work indicates that there should be an upcoming glacation regardless of any warming but the timing was and still is unknown. The panic was caused by the media reading timing as immediate into his work.

It's easy to be misled by the titles of papers. The examples you've asserted as supporting a 1970's perspective of global cooling don't actually do so.

Your second article sounds like it does:

Convection in the Antarctic Ice Sheet Leading to a Surge of the Ice Sheet and Possibly to a New Ice Age
T. Hughes, Science Vol. 170. no. 3958, pp. 630 - 633 (1970)

But it's just a potentially misleadingly worded title. If you read the paper it's got zero relevance to a possibility of a "new ice age" in the near (i.e. "near" from a 1970 perspective). It's about the GENERAL nature of ice Antarctic ice sheet advance that might (within a particular "surge" theory) be linked to the glacial cycles within the Pleistocene. So it's about how glacial periods might in general occur.

That's very clear from reading the paper. It's also evident just from reading the abstract:

abstract: "The Antarctic surge theory of Pleistocene glaciation is reexamined in the context of thermal convection theory applied to the Antarctic ice sheet. The ice sheet surges when a water layer at the base of the ice sheet reaches the edge of the ice sheet over broad fronts and has a thickness sufficient to drown the projections from the bed that most strongly hinder basal ice flow. Frictional heat from convection flow promotes basal melting, and, as the ice sheet grows to the continental shelf of Antarctica, a surge of the ice sheet appears likely."

So it's a theoretical study of a mechanism for ice sheet advance during glacial cycles. It doesn't address the possibility of any such event during the current Holocene, and has nothing to do with 1970's scientific perception of global warming or cooling or any such thing.

Although the title (and the rather odd abstract) might suggest that the paper is about the "return of the ice age", the question mark highlights the fact that the author is rather equivocal over such a conclusion.

Here's how he ends his (very brief) note:

"While there is an interesting parallel between recent and late-glacial events in the tropics, no clear cause-effect relation has been established between the current hemispheric cooling trend and precipitation trend in peninsular Florida. Also, even if a linkage were established, there is no certainty that the hemispheric cooling trend will not reverse itself in a few years. Rather than portraying a bleak future for Florida’s water supply, therefore, the observations presented here should serve as stimuli for further monitoring and research to promote understanding of the controlling atmospheric phenomena."

In other words, the paper relates to precipitation trends with potential implications for water supply in Florida, and the author indicates that there isn't any necessary relation between cooling and precipitation trends and indicates anyway that the cooling trend might reverse itself.

So neither of your suggestions - absolutely not the first one which is totally irrelevant to 1970's perspective on cooling/warming or otherwise, - nor the second one can be taken to support the notion of any 1970's scientific perception of global cooling (by the criterion that Paterson et al. set of a paper with a clear projection of climate change or discussing an aspect of climate forcing relevant to time scales of decades or centuries). Morgan's short note doesn't come to any conclusion - the "cooling" "...might reverse itself in a few years".

I was struck by this week's skeptic article (by David Deming in "The American Thinker"), [http://skepticalscience.com/article.php?a=2327] finding it both laughable and inspiring, and it drew me back to here. One thing that surprised me a bit was Deming's claim that we don't know what causes ice ages. I thought it was Milankovitch cycles mostly (Deming says Ike Winograd disproved that). With the google I only found a Wunsch abstract [http://tinyurl.com/qg3bgw] that says orbital changes only explain 20% of the variance in climate records studies. Anyway, I'm curious to learn more about our understanding of ice ages.

You SAY it is 'sounder science', but you ignore all the evidence to the contrary presented in this article and many others on this site.

No, belief in impending glaciation is NOT 'sounder science'. Nor is it "sounder science" to argue as you do, that it has always happened that way.

On the contrary: the SOUND science recognizes that things are no longer going to happen "as they always have happened". Now we really have made a large enough change to break the age-old pattern -- for the worse.

This Basic Version is one of the better ones written so far. It has much better flow as we read it. One idea logically follows after the other, leading naturally to a sound conclusion.

Well and good: but you knew there was a 'but' coming, didn't you;)? That 'but' is: "but the sentences are too long for our target audience".

To remedy this, I suggest some strategic application of metonymy, synecdoche and ellipsis to tighten things up.

So, for example, we can do much better than "As a result some scientists suggested that the current inter-glacial period could rapidly draw to a close, which might result in the Earth plunging into a new ice age over the next few centuries."

We can instead, say "So some scientists suggested that the current inter-glacial could draw to a rapid close, starting a new ice age over the next few centuries". (we really don't need to specify that it is the Earth we are talking about).

Similarly, "This idea could have been reinforced by the knowledge that the smog that climatologists call ‘aerosols’ – emitted by human activities into the atmosphere – also caused cooling." can also be improved by replacing with:

"About the same time, climatologist learned that 'aerosols' (small particles resulting from human activities) can cause cooling. This may have have encouraged the idea that a new ice age was coming".

One final note: here in the States at least, we use "it's" as a contraction for "it is". We never use it for "it has". I don't know about the state of the language Down Under, but if the target audience is here in the US, the use of "it's" to mean "it has" will sound strange to too many in your target audience.

Abstract
1) Three indices of global climate have been monitored in the record of the past 450,000 years in Southern Hemisphere ocean-floor sediments. 2) Over the frequency range 10(-4) to 10(-5) cycle per year, climatic variance of these records is concentrated in three discrete spectral peaks at periods of 23,000, 42,000, and approximately 100,000 years. These peaks correspond to the dominant periods of the earth's solar orbit, and contain respectively about 10, 25, and 50 percent of the climatic variance. 3) The 42,000-year climatic component has the same period as variations in the obliquity of the earth's axis and retains a constant phase relationship with it. 4) The 23,000-year portion of the variance displays the same periods (about 23,000 and 19,000 years) as the quasi-periodic precession index. 5) The dominant, 100,000-year climatic [See table in the PDF file] component has an average period close to, and is in phase with, orbital eccentricity. Unlike the correlations between climate and the higher-frequency orbital variations (which can be explained on the assumption that the climate system responds linearly to orbital forcing), an explanation of the correlation between climate and eccentricity probably requires an assumption of nonlinearity. 6) It is concluded that changes in the earth's orbital geometry are the fundamental cause of the succession of Quaternary ice ages. 7) A model of future climate based on the observed orbital-climate relationships, but ignoring anthropogenic effects, predicts that the long-term trend over the next sevem thousand years is toward extensive Northern Hemisphere glaciation.

A model of future climate based on the observed orbital-climate relationships, but ignoring anthropogenic effects, predicts that the long-term trend over the next sevem thousand years is toward extensive Northern Hemisphere glaciation.

I guess this is the correct thread to post my anecdotal evidence. I am really shocked by the display of revisionist history in the "What the science says" section. I have a BS in meteorology, 1979-1982. Some of the classes included physical meteorology, planetary atmospheres, air pollution, taught by both American (one at NASA) and European professors. We were taught that the Earth was in the last phase of an inter-glacial period and through a process called instantaneous glaciation, we could plunge into another ice-age within a few hundred years. We were taught that the runaway greenhouse effect occurred on Venus because the atmosphere never reached saturation vapor pressure and eventually all of the water boiled off into space. Here on Earth we were lucky, water condensed out to form the oceans, stabilizing the climate. Nothing about Anthropogenic Global Warming (AGW) being a threat, sorry, I wasn't taught that. I asked a colleague this morning what he was taught in the 70's and he said the same thing, global cooling.

In 1981 I had chance to take a summer class with Dr. James Hansen in planetary atmospheres but didn’t get in, made first alternate. Maybe Dr. Hansen would have introduced me to the concept of AGW but since I could not attend I can’t tell you what he taught in that summer class.

In order it to be complete anecdotal evidence, could you tell the name of the institution you did study at? name of some professors and/or heads of department? name of a couple of books you may have used in the subjects you named, and still keep in your bookshelves? and succinctly what did you do with your degree in meteorology (professionally speaking)?

If you want, I can explain why is this very important. Thanks in advance.

Perhaps your university, like many, suffered from a conservative bias among faculty. Some university geology departments taught 'continental foundering' for years as evidence for plate tectonics piled up. That doesn't prove anything about the current state of the science.

But the signs were there: Hansen published a paper on warming in 1981; the predictions reflected the early nature of the science, but they were substantially correct.

See also this article with links to earlier publications and a link to a video from 1989.

You've introduced a term I had never heard of before, "instantaneous glaciation", which seemed odd. If you search Google for it there are only 179 matches - two of which are actually links to your usage here. If you search Google Scholar you find only 15 matches, if you search Google Ngrams, it doesn't appear at all.

The term is, for all practical intents and purposes, not used. I suspect you are mis-remembering a 30 year old class.

Next, the assertion made in this article is that the majority of predictions in the 1970s were for warming, not cooling. That is not a question that an anecdote can answer. The writer demonstrated his thesis - the vast majority of papers in the field from the mid-1960s through the 1970s predicted that warming, not cooling, was in our future.

Three to four decades later, it is clear they were absolutely correct.

Maybe first we could wait until thepoodlebites #21 provides more information.

By the way, thepoodlebites, were your colleague taught in the same institution? the same grade? can you ask him/her?

Not that I think that muoncounter's and snowhare's comments are nothing but excellent, but I think that the first comment would be better once thepoodlebites provide basic information, and the second one is excellent once no information is provided.

We have to consider that the success of skepticalscience.com -10% more visitors each month- is going to drive more people of every kind and with that in mind it would be not advisable to engage in debates when incomplete information is provided without first ask the commenter to provide whatever in good faith he or she may have considered unnecessary.

"AN instantaneous glaciation model for the formation of the large Pleistocene ice sheets..."

so maybe the poodle has a case?

The abstract then says...

"I suggest here that such a survival could have resulted from one or several closely spaced massive volcanic ash eruptions."
or maybe the poodle is being highly selective in his interpretation of the relevance of this.

People really shouldn't go round destroying their own credibility that way, especially when they've spent that much time building it up.

I've tried to post replies but my posts are being pulled. What's the point of continuing the discussion when only one side is being represented? The posts concening my college experiences is true. Why do you question my veracity and censor my replies?

Response: [Daniel Bailey] I see only one deleted comment. That comment was deleted as it contained an inflammatory comment about another poster here on Skeptical Science. Keep the dialogue on the science and on the subject matter of the post (being off-topic is a prime reason comments get pulled) and all will be well.

muoncounter, Re:PDO; "So you are claiming that correlation requires causality? Did you run that past the denial establishment to see if they reached a consensus on that?" Is this post not inflammatory? Shouldn't all inflammatory comments be pulled? Some comments are more inflammatory than others I suppose.

...so we still wait for the name of the elusive institution of learning thepoodle went to ?
I was a science major (starting in 1977) at the University of South Florida... (Tampa and St. Pete campuses) and we were learning about global warming in 3 of my classes I remember .. Ecology and both Biological and Geological Foundations of Oceanography ... talking about the physics and looking at the CO2 level data from Mona Loa and some temperature prediction models (which turned out to be remarkably accrate, I might add)
It was even mentioned in my high school Biology class in 1975 (Kaiserslautern American High School, Germany)
I don't remember anything about global cooling except a few referrals to media coverage ....

At the intermediate level, this is the final sentence in the caption for Fig. 1 ... "In no year were there more cooling papers than warming papers."

Yet it appears in that very chart that there were more cooling than warming papers in 1971 (2 vs. 1).

Am I misinterpreting either the chart or the assertion in the caption?

The basic premise remains solid that climate papers in the period leaned heavily towards suspected warming, but it's best to correct overreach, before the "doubt mongers" use your own words against you.

I decide to give them a second chance and push on past the Newsweek reference, and then past the Washington Times, New York Times, and Times Magazine references to find the 1975 NAS report on "Understanding Climate Change". That report did not make any predictions and the coming ice age discussed was several millenia out based on orbital parameter variation.

#34 I'm just starting to review some of the relevant articles, W.S. Harley (1979) concludes "evidence of a change to a cooler regime has been found in the East Asia areas in each season except winter, in the Eastern North American area in winter, and in the Central Atlantic area in the spring and summer." And "no evidence of climatic warming is found."

That Climate Depot 'Factsheet' is a nonsense.
There are links to newspapers, blogs and books (many repeated or referenced more than once); broken links to the US Senate; and the use of the usual suspects, i.e. IceCap, JohnDaly and Inhofe, as well as such charming sites as AlGoreLied and PeopleForGlobalWarming.
The only properly sourced links (three of them at the end) are :

A broken one to AMS.

One to an AMS paper (which does work) which states :

If the actual ratio a/b of most tropospheric aerosols is of order unity, as inferred by previous authors, then the dominant effect of such aerosols is warming except over deserts and urban arms where the effect is somewhat marginal between warming and cooling.
(WHERE a/b is "the ratio of absorption a to backscatter b of incoming solar radiation by the aerosol")Suggestions by several previous authors to the effect that the apparent worldwide cooling of climate in recent decades is attributable to large-scale increases of particulate pollution of the atmosphere by human activities are not supported by this analysis.

The third link is to a book by Siegfried Fred Singer (!), which goes to a paper by J. Murray Mitchell Jr of NOAA, but which cannot be viewed in its entirety.
However, the abstract states :

A 32% increase of atmospheric CO2 over 1850 levels is predicted by 2000, causing an estimated 0.6 deg C increase in the global equilibrium temperature. This warming effect may be offset to a certain extent by cooling due to anthropogenic particle loading; in addition, CO2 input is expected to decrease as the consumption of fossil fuels decreases. It is observed that, although there is substantial evidence of global climate trends in the last century, such variations have occurred in the past as the result of natural processes.

But even the portion of it that can be viewed from Singer's book states that CO2 is the dominant effect, which could have greater effects in the future, thereby causing warming. And it suggests volcanic ash as the explanation for the cooling from the 1940s.

If all of that is proof of a 70s 'Coming Ice Age' claim, it is very poor.

#37 I find myself at a disadvantage here. If I answer your question my post most likely will be deleted, evaluated as an off-topic opinion. I'm finding the Climate Depot's link a valuable resource. I cited one peer-reviewed paper that supports my argument and I can cite many others, here. I will provide more links if this post is not deleted. Richard Feynman's first principle of scientific integrity states "you must not fool yourself, and you are the easiest person to fool. After you have not fooled yourself, it's easy not to fool other scientists." This first principle should be applied to everybody in equal proportion.

thepoodlebites, it is difficult to know what argument you are trying to support, especially as the first paper you linked to (W.S.Harley) also stated : "Thirty years of data are found of insufficient length to determine whether the cooling constitutes a climatic change under the given criteria";
and the second one (Barry Et al) concludes the introduction with : "The evident sensitivity of this area to climatic fluctuations on both short and long time scales makes it a rewarding area for interdisciplinary environmental studies".

thepoodlebites - the question is whether the scientific consensus was that planet was cooling. You can find papers noting long term negative turn in solar forcing, and plenty on aerosol cooling but also considerable concern about warming. Was there a consensus like there is on AGW now? Was there even a slim majority worried about cooling? You can only answer those questions of with systematic survey of scientific literature, not picking papers.(eg Peterson)

As for Climate Depot - how many examples of misinformation would we have to show you before you abandoned it? 5, 10, 100, every post, - or never so long as it says things you want to hear. (ie is it worth our time trying?)

#39 Your Barry et al. link is broken. Read just before the sentence you quoted, "the summer cooling is apparently widespread through the Canadian Arctic so that a larger scale control must be sought." A thorough scientist will recommend the need for further study when a cause for the observed trend can not be conclusively determined.

The Ice Age is not over and we are still in an Ice Age climate. Ice Age conditions first appeared on the Earth about 45 million years ago with the appearance of permanent ice sheets in Antarctica. The other feature of this ice age climate was the sharp drop in the concentration of CO2 which dropped from several thousand ppm 50 million years ago to levels as low 150-250 ppm as recently as 3 million years ago. Today we have a CO2 level of 380 ppm and most of Antarctica and Greenland are still covered with ice. The great ice sheets have at their maximum reached as far south as 40 deg latitude. Burying much of North America, Europe and Siberia. How do we know all this? 100,000s of ocean core samples collected since the Second World War when studies of the oceans and atmosphere became a priority for the US military. In addition to establishing our world's paleoclimate it also proved that the continents move on giant rocky plates. The message I take from this is that life on Earth can globalize and cope with a great range of climate and has survived worse climate upsets like those 65 and 250 million years ago. It will be a different place and there is no guarantee man will flourish in such a brave new world. Much of the flora and fauna didn't pass muster 65 and 250 million years ago.

Found a much more recent paper, which is talking about a return to ice age conditions in the near future

From the summary, published in 2000:
"The solar-output model allows speculation on global climatic variations in the next 10,000 years. Extrapolation of the solar-output model shows a return to little-ice-age conditions by A.D. 2400–2900 followed by a rapid return to altithermal conditions during the middle of the third millennium A.D. This altithermal period may be similar to the Holocene Maximum that began nearly 3,800 years ago. The solar output model suggests that, approximately 20,000 years after it began, the current interglacial period may come to an end and another glacial period may begin."

Response: [Dikran Marsupial] Neither of these articles is of relevance to a discussion of predictions of an impending ice age made in th 70s. Please familiarise yourself with the comments policy, off-topic posts are normally deleted in order to keep the discussion focussed. I'll happily discuss the first article with you on a more appropriate thread. Note that the second article does not appear to be supported by any peer-reviewed science, unlike the statement by the Royal Society, which suggests some skepticism is in order.

cjshaker wrote: "Found a much more recent paper, which is talking about a return to ice age conditions in the near future

'This altithermal period may be similar to the Holocene Maximum that began nearly 3,800 years ago. The solar output model suggests that, approximately 20,000 years after it began, the current interglacial period may come to an end and another glacial period may begin.'

cjshaker, no you didn't misread that... but it says "little-ice-age", while you said "ice age". These are not the same thing.

The 'little ice age' was a brief comparatively minor cooling period centered around north western Europe.

Technically, the term 'ice age' refers to any period where portions of the Earth are covered with ice caps... making the past several million years part of an ice age. However, the term 'ice age' is also often used to refer to glaciations (i.e. periods when the ice caps expand significantly)... which the quote you provided suggested could next occur in 20,000 years.

Thus, reading your prediction of an 'ice age in the near future' as referring to a glaciation would be consistent with common usage of the terms. I have never before seen the term 'ice age' treated as synonymous with the 'little ice age'. One is a term used for two different types of global cycles that play out over hundreds of thousands to millions of years... the other was a localized phenomenon that lasted a couple hundred.

That said, I wouldn't generally call 300 to 800 years from now the "near future" either. In any case, the topic of this post is global 'ice age' / glaciation. A return to 'little ice age' conditions would be a problem for Europe, but a non-event for most of the planet.

cjshaker wrote: "It seems that asking questions and then thinking about the replies is a problem?", no, not at all, but after thought about the replies, it is both polite and constructive to post your thoughs regarding the replies, rather than to simply move on.